b'economically on a large scale in Idaho, the test treesmeant that certain ground water users may be subject have performed well so far. According to researcherto curtailment in the 2019 irrigation season if they Sara Mahdavi, So far, the quality, fruit weight and fruitwere not participants in, or not in compliance with, an number are very acceptable. The number of fruits andapproved mitigation plan. Moreover, water litigation yield are very comparable [to commercial varietieshas often resulted over conicts between Snake River grown in other areas] and they are good. surface water users who have senior water rights under the basic principle of Idaho water law, rst in The primary concern of growers and researcherstime, rst in right, and ground water users with junior remains whether the trees can survive Idahos coldestwater rights in the ESPA. Thus, the Director of IDWR winters. The almond trees in the Parma study haveis required to issue an order at the beginning of each passed three cold-weather events so far, and they haveirrigation season to apportion any shortfall in water even faired better than peach, plum, and apple trees insupply to the senior surface water right holders and the area. However, UI researchers say they need two orto determine the obligations of junior ground water three more years of data before a denite conclusionpumpers to curtail water use or mitigate for depletions can be reached on the viability of large scale Idahoanto the holders of senior priority water rights.12almond orchards.9In addition to using ground water for agricultural IRRIGATION AND RESERVOIRS activities, surface water storage in the form of reservoirs is a critical factor to protable agriculture. Drought poses a direct threat to the success of IdahosEarly pioneers began building irrigation networks agricultural sector. Production of potatoes and troutsuch as dams and canals more than 150 years ago. will be impacted by drought, and Idaho is the biggestBeyond storing water for agriculture, municipal, producer of each.10 Irrigation has been an essentialcommercial, and industrial uses, reservoirs create the component in the battle against drought and aridadded benet of ood risk reduction, hydropower conditions. At 2.8 million irrigated acres, Idaho, whichgeneration, wildlife habitat, and recreation ranks 39th nationally in population, ranks second in totalopportunities. The majority of above-ground water irrigation withdrawals. Furthermore, 97 percent of waterstorage volume in Idaho is impounded by dams withdrawn in Idaho is used for agriculture, comparedowned and/or regulated by various federal agencies with 77 percent in California, 88 percent in Oregon andtotaling approximately 12.9 million acre-feet.1368 percent in Washington. Due to its desert climate,According to the National Weather Service-Boise,the southern portion of the state accounts for most of this water usage. Farmers are heavily dependent onReservoir storage across Idaho was in good shape the reservoir and aquifer systems to grow their cropsas of early March with major reservoir systems because there is far too little precipitation throughoutholding near average or well above average water. the growing season. According to University of IdahoAcross southern Idaho, reservoir storage in the Agricultural Economist Garth Taylor, [Irrigation is] ourBear River Basin and Southside Snake River Basins competitive advantage; we have water here in the state,was 144 to 153 percent of average. Storage in West why not use it to produce food in Idaho. Were using ourCentral Basins, Wood and Lost Basins, and the water to create wealth and feed the world. Fortunately,Upper Snake River Basin ranged from 110 to 168 the Snake River Valley hosts rich aquifer system topercent of average. Meanwhile, reservoir storage support irrigation and total water withdrawals in Idahoin the Clearwater and Panhandle Regions was have declined since the 1970s thanks to more ecient96 to 104 percent of average. Weather patterns, watering practices.11 irrigation demand, and \x1eood control needs will drive reservoir operations over the next several Yet, aquifer levels are not what they used to be. Inmonths. Wet spring weather or extended periods April 2019, the Director of the IDWR issued a waterof above normal temperatures resulting in rapid order predicting a 20,900-acre-foot shortfall to seniorsnowmelt could result in signi\x1dcant increases in priority surface water rights in the ESPA region in thereservoir out\x1eows and river levels. 14upcoming irrigation season. The shortfall prediction 14 I D A H O I N F R A S T R U C T U R E G U I D E B O O K'